Investigating the effects of mesotrione/atrazine-based herbicide on honey bee foragers

• Published in: The Science of the total environment Vol. 898; p. 165526
• Main Authors: Araújo, Renan dos Santos, Viana, Thaís Andrade, Botina, Lorena Lisbetd, Bastos, Daniel Silva Sena, da Silva Alves, Beatriz Cristina, Machado-Neves, Mariana, Bernardes, Rodrigo Cupertino, Martins, Gustavo Ferreira
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.11.2023
• Subjects: Calaris; Hemocytes number; Locomotion activity; Midgut histology; Nitrosative stress; Oxidative stress; Locomotion activity; Oxidative stress; Hemocytes number; Nitrosative stress; Calaris; Midgut histology
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.165526

A mixture of the herbicides mesotrione and atrazine (Calaris®) is a widely used herbicide in agriculture in several countries. However, the possible toxicological effects of this formulation on non-target organisms require investigation. In this study, the effects of acute oral exposure to Calaris® were evaluated in Apis mellifera foragers. The effect of seven different concentrations of Calaris® on survival and sucrose consumption was studied, while the recommended concentration for field use (FC) and its 10× dilution (0.1 FC) were used to assess overall locomotor activity, respiratory rate, flight, midgut morphology, oxidative and nitrosative stresses, and hemocyte counting. The exposure to FC or 0.1 FC decreased locomotor activity and induced damage to the midgut epithelium. Additionally, the two tested concentrations reduced superoxide dismutase activity, nitric oxide levels, and total hemocyte count. FC also increased malondialdehyde content and 0.1 FC increased respiratory rate and decreased the proportion of prohemocytes. Overall, our findings evidenced significant harmful effects on A. mellifera foragers resulting from the ingestion of the Calaris® herbicide. [Display omitted] •Effects of Calaris® herbicide on honey bees were assessed via acute oral exposure.•The treatments had no effect on bee survival and diet consumption.•Exposure to herbicide concentrations decreased locomotor activity.•Exposure led to an increased respiratory rate.•Exposure induced morphophysiological damage to the digestive and immune systems.